The invention pertains to a magnetic induction flowmeter to measure the rate of flow of a fluid, with a tubular section of a plastic flow element adjoining a flow channel and also with electrodes permeating the tubular section and positioned at a distance from each other in the flow channel. A method suitable for production of a magnetic induction flowmeter also lies within the scope of the invention.
In the case of magnetic induction flowmeters, the measurement principle requires a contact with the fluid medium at a minimum of two locations. In known flowmeters, metal pins or caps are used as electrodes in the flow element; these electrodes pass through the wall of the pipeline and are connected by electrical lines. In this case, the installation of the electrodes into the flow element is done either immediately during the manufacture of the flow element in an injection molding step, where the metal pins are installed into the mold and are enclosed by the molding compound, or the metal pins are subsequently pressed into the flow element.
One significant disadvantage of the known electrode contacts with metal elements is that a dependable seal between the metallic electrodes and the surrounding plastic of the flow element is not assured over a longer period of time. The leaks ultimately occurring will require disproportionately expensive repair activities.